Abstract: This paper is concerned with the absolute stability problem for observer-based Lurie networked control systems. Due to utilizing observer-based dynamic feedback controller, the network-induced delays can not be simply thought as the sum of the sensor-to-controller delay and the controller-to-actuator delay. First, the Lurie networked control system is modeled as a multiple delay Lurie system by the state augment approach. Then, a delay-dependent stability condition is established via Newton-Leibniz formulation and free weighting matrices. Based on the obtained result, three approaches to calculate the controller gain matrix and the observer gain matrix are proposed. We also present the robust stability condition and robust controller design approach for Lurie networked control systems with norm-bounded uncertainties and structured uncertainties. All the results are formulated in terms of linear matrix inequalities (LMIs), which are easily solved via the LMI toolbox in Matlab. Finally, two examples are worked out to illustrate the feasibility and effectiveness of the proposed approaches.